Medusa

Medusa is an open-source, headless commerce platform that gives developers the building blocks to create completely custom online stores and commerce experiences. Often described as an open-source alternative to closed platforms, Medusa provides the commerce engine — products, carts, orders, payments, fulfillment, discounts and more — as flexible, modular Node.js infrastructure you fully control, rather than a rigid hosted store you have to bend to your needs.

The headless, API-first architecture is the key. Medusa handles the backend commerce logic and exposes it through APIs, while you build any frontend you like — a Next.js storefront, a mobile app, a marketplace, or something entirely bespoke. This decoupling gives teams the freedom to craft unique shopping experiences and integrate commerce into existing products, without the constraints of templated themes or platform lock-in. Because it's open source, you can self-host it, read and modify the code, and avoid per-transaction fees and revenue caps.

Medusa's modular design means you can use as much or as little as you need and extend it with plugins for payments, search, notifications and integrations, or write custom modules for unique business logic. This makes it a strong fit for businesses with requirements that off-the-shelf platforms can't meet — complex catalogs, B2B flows, multi-region setups, subscriptions or custom checkout experiences. Backed by an active developer community and increasingly capable tooling, Medusa appeals to engineering teams and agencies that want the power and freedom of building commerce their way, with the transparency and cost advantages of open source rather than the limitations of a closed, hosted platform.